Floating deck or roof for liquid storage tanks



J. H. WIGGINS FLOATING DECK OR ROOF FOR LIQUID STORAGE TANKS Filed Nov. 9, 1922 Dec. 30, 1 9 24.

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JOHN E. WIGGINS, OF

swarms DECK OR ROGF FOE; LIQUID STOGE t Application filed November 9, 1822. Serial No. ceases.

To all whom it may concern:

Be it known that I, Jenn HfWIocrNs, a citizen of the United States, residing at Bartlesville, Oklahoma, have invented a certain new and useful Improvement in Floating Decks or Roofs for Liquid Storage Tanks, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertainsto make and use the same.

This invention relates to liquid storage tanks of the type that comprise a deck on roof which normally floats upon the liquid in the tank.

One object of my present invention is to provide a floating deck or roof for liquid storage tanks that is equipped with a relatively deep truss which is combined with the deck in such a manner that the truss members do not roject upwardly above the top side of the eck to such a height that they will interfere with any transverse tie members or braces that extend horizontally across the tank and do not pro'ect downwardly from the underside of t e deck to such an extent as to make it impracticable to use an inside truss vfor reinforcing and strengthenin the deck. v

Another 0 ject is to provide a trussed floating deck or root of simple design and inex ensive construction in which the truss mem rs will always be taut. I

And still another object'is to rovide a. means for draini the top sur ace of a float deck or roe which rests upon oil or other liquid that is of less a ecific gravity than water, that overcomes t e necessity of using a jointed. drain ipe to provide for the rise and fall of the eck, due to variations in the level of the liquid in the tank. Other objects and desirable features of my invention will be hereinafter ointed out.

To this end I have devised a floating deck or roof for liquid storage tanks that is equipped with a dee t which is comhined with the deck in such a manner that some of the truss members are arr above the'deck and the render of the truss members are arranged on the underside of the deck. The truss preferably comgrises a vertical strut at the center of the eck composed of a member arranged above the deck and a member arranged on the underside oi the deck, a plurality of radially disposed compression members on the underside of the deck arged. appro teiy it pcits water to drain from the top the upper end of the center strut and the other being secured to the deck and to the outer end of the particular compression 'member with which it co-operates. Means is provided for adjusting some of the members of the truss so as to insure that the co operating elements of the truss will alwas.

be tent, and while various means may 1 used for this purpose without departing from the spirit of my invention, I refer to use a means that can also be use for defleeting the central portion of the deck so as to increase the buoyancycof the deck and also produce a depressed portion in the it side of the center of into whi water on the surface of the deck will drain;

previously stated, one object of my present invention is to eliminate the jointed dreinfiplpe that is generally usedlior carrymg 0 water from the top side of a floating deck or roof for oil storage tanks. I accomplish this desirable result by using one or more inverted siphons, each of which comprises a draining device that leads from the top side of the deck and which terminates inside of the tank in such a way that while side of the deck into the bottom oi the tank at a point below the oil in the tank, it will not permit the oil in the tank to escape upwardly through said draining device, due to the fact that the oil in the tank is of less specific gravity than the water in said drainina device. The draining device just referred to can be constructed in various ways. so long as it is of such desi that it will virtually form a U-shaped tube filled with water and having a long leg communieating at its upper end with the surface ta be drained and a short leg which terminates inside of the tank. Normally. the water stands in the long leg of said tube at such a level that it balances the liquid in thetaq thereby efiectiveiy cutting ofii the escape of the liquid in the tank through said tube Whenever additional water enters the long leg of said tube from the surface to be drained, namely, the top side of the deck of the tank, the siphon becomes unbalanced and some of the water in said tube escapes therefrom into the lower portion of the tank, wherein the water collects at a point below the body of liquid in the tank. At intervals the water 1n the bottom portion of the tank is allowed to escape by opening a drain cock or valve in the lower portion of the tank. In the form of my invention herein illustrated the inverted siphon or substantially U-shaped draining device above referred to is formed by a vertically-disposed pipe arranged so that water can flow into same from the top side of the deck of the tank and a depending extension on the bottom of the tank that receives the lower end ortion of said tube, said extension being ong enough to provide for the rise and fall of the deck, due to variations in the levelof the liquid in the tank, and the upper end of said extension being in direct commun1= cation with the tank-so that the drain water i which enters said extension from the lower end of the drain pipe can flow upwardly into the tank and collect therein at a point below the body of oil or other liquid in the tank. I do not wish it to be understood, however, that my invention is limited to a draining device formed by a deplendin drain pipe on the floating deck of t e tan and a depending extension on the bottom of the tank which receives the lower end portion of said drain pipe, as the same result can be accomplished in various other ways without de arting from the spirit of my invention. h urthermore, while I have herein illustrated my improved draining means used in connection with a trussed deck or roof, I wish it to be understood that it is not limited to use ,with such a deck, but is capable of use with any type or kind of deck that floats upon a body of liquid of less specific gravity than water.

Figure 1 of the drawings is a diagrammatic view on a reduced scale, illustrating how the radially-disposed tension members and the compression members of the truss of the deck are arranged; and- Figure 2 is a vertical transverse sectional view of a portion of an oil storage designates tank equipped with a floating deck embodying my invention, said view being taken on approximately the line 2-2 of Figure 1.

Referring to Fi ure 2 of the drawings, A designates the cy indrical side wall of a tank that is used for storing oil or other liquid of less specific gravity than water, B

the bottom of the tank and C designates the central bod portion of a deck or roof that normally oats upon the liquid in said tank. The central body portion C of the deck is preferably formed from thin ripheral portion of the deck described in either of m pending ap lications for patents Serial 0. 540,847, led March 3, 1922 and Serial No. 599,903, filed November 9, 1922. One feature of my pi esent invention consists of a truss of novel construction for reinforcing and strengthening a deck or roof that floats upon a body of liquid in a storage tank. Said truss comprises a verticall dis osed strut arranged at the center of t e dec C and composed of a. member D arranged above the deck with its lower end bearing against the deck and a member D arranged slow the deck with its upper end rigidly connected to the deck, a plurality of radially-disposed compression members E on the underside of the deck arranged substantially parallel to same with their inner en'ds joined to the center strut and their outer ends joined to vertically-disposed struts F whose upper ends are rigidly connected to the deck, and a plurality of radially-disposed tens'on members connected at their inner ends to the upper end of the center strut and connected at their outer ends to the outer end portions of the compression members E, each of said tension members comprising a part G .arran ed above the deck and apart G arranged elow the deck, as shown in Figure 2, both of whichparts are rigidly connected to the deck. Means is rovided for adjusting certain members 0 the truss so as to insure that the truss members will always remain taut, and thus be in a condition to immediately counteract any unequal load that is applied to the deck, and while various means ma be used for this purpose, it prefor to equip the part G of each of the tension members with a turn-buckle 1 and secure the inner end of the part G of each tension member to a-vertically-adjustable lit) be exerted on the deck 0 suflicientl to deflect the central portion of the deck, as shown in Figure 2. This deflection of the central portion of the deck not only imparts greater buoyancy to the deck, but it also causes a depression to be formed in the top side of the deck at the center of same into which water on the top' side. of the deck naturally drains. The operation of tightening-the turn-buckles 1 takes up the slack in the membersof the truss that are arranged on the underside of the deck 0, the compression members E held rigid by verticallydisposed, de ending braces 4 on theunderside of the eck, and the inner ends of said compression members bein rigidly connected to the bottom mem er 1) of the center strut by means of a hollow connecting member H from which said compressions members E branch radially. So far as trussing of the deck is concerned, 'it is immaterial Whether the compression members and the struts are formed from solid rods or pieces of tubing, but in order to simplify the construction of the deck and enable some of the truss members to be used as conduits for carrying ofl rain that falls on the deck, I prefer to construct the compression members E from pipes and construct the struts F and the lower member D of the center strut from pieces of pipe, the hollow connecting member H that is used to join the compression members E to the center strut consisting of a drain manifold that-connects all of the radially-disposed drain pipes E with a vertically-disposed drain pipe D arra ed at the center of the deck.

T is method of constructing the deck makes it practicable to equip the deck with a relative y deep truss, due to the fact that some of the truss members are arranged above the deck and someof the truss members are arranged below the deck, thereb preventing the truss members above the dec from interfering with any transverse tie members that may be used to brace the side wall of the tank and those beneath the deck from seriously interfering with the downward movement of the deck during the operation of drawing the liquid out of the tank. Another desirable feature'of such a deck is that it can be manufactured at a low cost, due to the fact that standard pipe and pipe fittings may be used to form most of the members of the truss, the vertical struts consisting of pieces of pipe that are screwed into collars 5 that are welded to the deck or connected to same in any other suitable way. The depressed central portion of the deck imparts-great buoyancy to t e manifold H is suspended, and as means is prov'dedv for taking upthe slack in the radially-disposed tension members, the various elements of thetruss can be kept taut art of the deck from which the drain water in the pipe I and the pipes D7, E and F enough to insure thetruss immediately counteracting any uneven loads that are applied to the deck.

As previously stated. one feature of my present invention consists of a (ll ainagc means for a floating tank deck or root which is constructed in such a way that it is not necessary to use a jointed or flexible drain pipe to provide for the rise and fall of the deck, due to variations in the level of the liquid in the tank. This improved drai= age means may be described briefly as consisting of one or more inverted siphons, each of which is composed of a draining device communicating at its upper end with the top side of the deck or with a drain pipe that leads from the top side of the deck and having its lower end terminating inside of the tank in such a way that water which falls onto the desk will be conducted by said draining dcvice'down into the lower portion of the tank at a point below the body of liquid in the tank. Inthe form of my invention herein illustrated the draining device just referred to is formed by a vertically-disposed drain pipe I that forms a continuation of one of the vertical struts F of the truss and which projects downwardly into a depending extension 1' on the bottom B of the tank, said extension I being lon enough to provide for the rise and fall of t e deck C, due to variations in the level of the liquid in the tank. Rain that falls on the top surface of the deck C will be conducted by the tubular truss -members 1), E and F to the drain pipe I down through which it flows into the dependlng extenslon I on the bottom' of the tank.

the drain water passing upwardly through the extension I, as indicated by the arrows in Figure 2, and finally collecting in the bottom of the tank at a point below the body of liquid in the tank.;on which the deck C floats. bottom of the tank contains sutlicient drain water to seal the lower end of the drain pipe I, and said drain pipe, as well as the members D, E and F of the truss, are filled with drain water, the normal level of the drain water in the members D and F of the truss being indicated by the reference character :12 in Figure 2. Notwithstanding the fact.

that the level of the liquid in the tank is higher than the level of the liquid 'in the pipes D and F that lead from the top surface of the deck C, it is impossible forthe liquid in the tank to escape upwardly through the drain pipe I and the pipes D. E and F that communicate with same due to the fact that the liquid in the tank, which I will assume is oil or a similar substance, is of less specific gravity than the drain with which it communicates. When rain falls on the deck it will eventually find its way into the dram pipes D and F, thereby Normally, the extension I on the increasing the weight of the column of drain water that opposes the column of oil in the tank, and consequently, causing the siphonto become unbalanced, whereupon more water will. flow upwardly through the extension i on the bottom of the tank and collect in the tank beneath the body oi oil therein. At frequent intervals excess drain water is removed from the bottom of the tank through a draw-oil pipe 6 that is provided with a valve 7. From the foregoing it will be seen that the drain pipe I and the extension I j on the bottom of the tank into which said drain pipe extends co-operate with each other to form practically a U-shaped tube filled with drain water and arranged with the upper end or its short leg communicating with theibody oi oil in the tank and the upper end of its long leg communicating with the top surface of the deck, the greater specific gravity of the column of water in said tube causing said column of water to act like a check valve to permit drain water enter the bottom of the tank and to cut ed the escape of the contents of the tank through said ill-tube. in addition to forming a very efiicient means for draining the top surface of the deck Q, the drain pipe ll" cooperates with the depending extension ii on the bottom of the tank to prevent the floating deck C of the tank from rotating or turning relatively to the side wall A of the tank. It is, of course, immaterial to what part of the draining system the'pipe l is connected, so.

long as the upper end of said pipe communicates with the surface to be drained, or with a system of drain pipes into which water flows from the surface to be drained. Moreover, while I have'hcrein illustrated the pipe downwardly into the extenl as projectin sion ll on the ottom of the tank, it will, of course, be obviousthat the same result could be accomplished by using a drain pipe leading from the draining system and having its lower end bent upwardly so as to produce a substantially Ll-shaped tube composed of a Iona leg and a short leg.

Having thus described my invention, what ll claim as new and desire to secure by Letters Patent is:

1. A. floating deck for liquid storage tanks rovided with a relatively deep truss comined with the deck in such a manner that some of the truss members are arranged above the deck and some are arranged below the deck,

2. A floating deck for liquid storage tanks provided with a truss comprising members arranged above and below the deck, and

means for adjusting said truss members so as to kee them taut.

3. A floating deck for liquid storage tanks provided with a truss comprising members arranged above and below the deck, and means for exerting pressure on the deck in such a way as to deflect the central portion or same and thus increase the buoyancy of the deck. 7

4. A. floating deck for liquid storage tanks provided with a truss comprising compression members and struts arranged on the compression members ont-he underside or" the deck that branch radially from said center strut, and tension members connected attheir inner ends to the upper end of said center strut and at their outer ends to said compression members.

6. A floating deck for liquid storage tanks, comprising a center strut that projects upwardly and downwardly from the deck, compression members on the underside of the deck that branch radially from said cen ter strut, vertically-disposed struts on the underside of the deck to which the outer ends of said compression members are con nected, and inclined tension members con nected at their outer ends to said compression members and at their inner ends to the upper end of said center strut.

7. A floating deck for liquid storage tanks, comprising vertically-disposed struts arranged on the underside of the deck at the center and at the outer edge of same, radially-disposed compression members on the underside of the deck connected to said struts, a center strut projecting u wardly from the top side of the deck, and inclined tension members leading from the outer ends of said compression members to the upwardly-projecting strut and connected to the deck at points intermediate the ends of said tension members.

8. A floating deck for liquid storage tanks, comprising a strut member projecting upwardly from the top side of the deck at the center of same, and inclined tension members connected to the upper end of said strut and to the deck.

9. A floating deck for liquid storage tanks, com rising a strut member projecting upwar ly from the top side of the deck at the center of same, inclined tension members connected to the upper end of said strut and to the deck, and means for verymg the point of connection between said tension members and strut so as to exert pressure on the deck in a direction tending to deflect the central portion of same.

top side of the center of the deck and hav- Mid iii)

'ing no direct connection with the deck,

a vertically-adjustable part on said strut member, and inclined tension members connected to said part and to the deck.

11. A floating deck for liquid storage tanks, provided with a trusscomprising members arranged on the underside of the deck and members arranged on the upper from pieces of pipe or tubing and arranged in such a way that they can be used to carry oil drain water from the top side of the deck. a

13. A floating deck for liquid storage tanks provided at its center witha depending drain pipe, a plurality of radially-disposed conduits that branch from said drain pipe, and an outlet leading from one of said conduits to the bottom of the tank.

14. A tank for storing oil or other liquid of less specific gravity than water, compris ing a floating deck, and means for draining the top surfacev of said deck and conduct ing the drain water down into the bottom of the tank below the body of oil in the tank.-

15. A tank for storing oil or other liquid of less specific gravity than water, comprising a floating deck, means for draining the top surface of said deck and conducting the drain water down into the bottom of the tank below the body of oil in the tank, and means for enabling the drain water to be removed from the lower portion of said tank. v

16. A tank for storing oil or other liquid of less specific gravity than water provided with a deck that floats upon the body of oil in the tank, and an inverted siphon for con-' ducting water from the top side of said deck into the lower portion of the tank below the body of oil therein.

'17.- A tank for storing oil or other liquid of less specific gravity than water provided with a floating deck, and a substantially U shaped draining means having the upper end of one of its legs communicating with the top side of said deck and the upper end of its other leg communicating with the .in- 'terior of the tank.

, 18. Atank'for storing oil or other liquid of lessspecific gravity than water provided with a floating deck, and means for drain- .ing thetop surface of said deck comprising a drain pipe projecting downwardly from the deck, and an extension on the bottom of the tank which receives said drain pipe.

19. A tank for storing oil or other liquid of less specific gravity than water provided with a floating deck, a vertically-disposed drain pipe projecting downwardly from the deck,. and an extension projecting downwardly from the bottom of the tank that is adapted to receive said drain pipe.

20. A tank for storing oil or other liquid of less specific gravity than water provided with a floating deck, and a drain pipe for conducting water from the surface of the deck into thelower portion of the tank, ar-

ranged so that it will normally be filled by a column of drain water that acts as a check valve to admit drain water to thevlower portion of the tank but which prevents the escape of either oil or drain water from the tank.

21. A tank for storing oil or other liquid of less specific gravity than water provided with a floating deck, a drainage means on the underside of the deck adapted to receive water that falls onto the deck, a drain pipe projecting downwardly from said means and a vertically-disposed extension on the bottom of the tank that receives said drain pipe and which is of such proportion relative to said drain pipe that the lower end of said drain pipe is always located at a point below the bottom of the tank JOHN H. WIGGINS. 

